Laos forum

try asking on lonely planet's thorntree forum SEA mainland branch - the very few i know who have travelled the Sayabouly-Pak Lay-Xanakham-VTE road post there & i don't see them posting on this forum. only did the LPB-Sayabouly section in Dec 2009, really dusty considering that it was a paved road. for some reason Sayabouly province seems to beat even Phongsaly in the 'dusty roads' contest.

don't think Sayabouly town (town itself pretty dust-free) will interest the average tourist unless the elephant festival is being held there (some years in Hongsa or Pak Lay instead) or you're there during Hmong New Year celebrations (which i was). it's surrounded by many many Hmong villages but lack of tourists means it's hard for trekking/other sorts of tours to take off.

have a look here: http://sayaboulytourism.com
will check again but till now i don't really recall anyone talking about Phieng or Thongmixay.

if travelling LPB to Saya town by public bus, my advice is to get to LPB southern bus station MINIMUM 1 hour before the morning bus is scheduled to depart. it's a 40+ seater that fills up quickly, & whoever & whatever can't squeeze on will start filling the afternoon bus, which can be full as early as 2-3 hours before departure.

the plan was to travel between Luang Prabang and Vientiane without going via Vang Vieng

if you could tell us the reason(s) for this, it'd be easier to suggest alternatives.

Posted from within Vietnam.

Have you considered flying? Lao Airline is actually not as expensive as thought, since their prices are fixed, independent on when you book, and no extra charges for food, luggage etc. We were in Luang Namtha a month ago, and when calculating the different options (time is also money) flying was the best option, and it gave us much more days to spend comfortably in Vientiane , instead of on a dusty road. And the outside view from the plane was not so bad either...

I visited Vientiane first time 2004 or 2005 and coming back last month and see the improvments was great. Only mistake we did, was not to have enough days, Vientiane is so beautyful and easy going, specially with the new public park along Mekong with outdoors gym (by the way a great place to meet local people when visiting in the early mornings)